I was doing the online tailing in order to get the silenced Kriss Vector ,45 ACP. Apparently that's the only way to get it and it's sooooooo darn sweet.

Also, the one on one hack while decidedly annoying when inflicted upon you is dreadfully fun from the other side. There's nothing like watching some poor fool running around looking for you when you're only ten feet away. Apparently, the most successful method appears to be hiding behind a square piece of concrete like a raised city garden or something or just hiding behind a car. You just keep moving around the car, keeping it between you. 

Which reminds me, now that I've restarted I need to get a new pump action grenade launcher. It's good for those situations. If you blow up every car nearby there's no place to hide :)